Gaming machine with variable trigger

Abstract

A gaming machine has a display and a game controller arrange to control images of symbols displayed on the display. The game controller is arranged to play a game wherein, if a predetermined special symbol outcome, comprising a plurality of special symbols, occurs in a base game, a player is afforded an opportunity of selecting one of those symbols. If, as result of that selection, a predetermined selection outcome occurs, a bonus feature is awarded.

I claim:  
     
         1 . A gaming machine comprising a display and a game controller configured to control images of symbols displayed on the display, the game controller being configured to play a game wherein, if a predetermined special symbol outcome, comprising a plurality of special symbols, occurs in a base game, a player is afforded an opportunity of selecting one of those special symbols and if, as a result of that selection, a predetermined selection outcome occurs, a bonus feature is awarded.  
     
     
         2 . The gaming machine of  claim 1  in which the predetermined special symbol outcome is the occurrence of a predetermined, minimum number of the special symbols in the base game.  
     
     
         3 . The gaming machine of  claim 1  in which the predetermined selection outcome is the occurrence of a trigger symbol.  
     
     
         4 . The gaming machine of  claim 3  in which the probability of the predetermined selection outcome occurring is related to the number of special symbols which occurred in the base game.  
     
     
         5 . The gaming machine of  claim 3  in which, if the predetermined selection outcome occurs, the selected special symbol changes into the trigger symbol.  
     
     
         6 . The gaming machine of  claim 5  in which the trigger symbol includes a device and a background scene.  
     
     
         7 . The gaming machine of  claim 6  in which the device of the trigger symbol moves from its starting position across the display and when the device reaches a side of the display, a screen display changes to an initial screen display of the bonus feature.  
     
     
         8 . The gaming machine of  claim 7  in which the initial screen display of the bonus feature gives the player a choice of bonus features to be played.  
     
     
         9 . The gaming machine of  claim 1  in which the special symbol is a scatter symbol.  
     
     
         10 . The gaming machine of any one of the preceding claims further comprising a selector for enabling the player to select one of the special symbols.  
     
     
         11 . A method of playing a game on a game playing apparatus, the game playing apparatus comprising a display and a game controller configured to control images displayed on the display, the method comprising the steps of, if a predetermined special symbol outcome comprising a plurality of special symbols occurs in a base game, affording a player an opportunity of selecting one of those special symbols and if, as a result of that selection, a predetermined selection outcome occurs, awarding a bonus feature.  
     
     
         12 . The method of  claim 11  comprising selecting the predetermined special symbol outcome to be the occurrence of a predetermined, minimum number of the special symbols in the base game.  
     
     
         13 . The method of  claim 11  comprising selecting the predetermined selection outcome to be the occurrence of a trigger symbol.  
     
     
         14 . The method of  claim 13  comprising relating the probability of the predetermined selection outcome occurring to the number of special symbols which occurred in the base game.  
     
     
         15 . The method of  claim 13  comprising, if the predetermined selection outcome occurs, changing the selected special symbol into the trigger symbol.  
     
     
         16 . The method of  claim 15  in which the trigger symbol includes a device and a background scene.  
     
     
         17 . The method of  claim 16  comprising moving the device of the trigger symbol from its starting position across the display and when the device reaches a side of the display, changing a screen display to an initial screen display of the bonus feature.  
     
     
         18 . The method of  claim 17  comprising offering the player a choice of bonus features to be played via the initial screen display.  
     
     
         19 . The method of  claim 11  in which the special symbol is a scatter symbol.